Thanks to the advice I received here I am very excited to actually be making accurate rounds for my 204 Ruger. After trying out 6 different loads I am using Vihta N-540, Rem 7&1/2 primers, V-Max bullets seated to 2.245. My 5 round groups are usually touching one another so I am very happy to say the least. Here's what's troubling me so I again hope to find the answer here.
I am using a Redding Boss Press with a Redding Competition Seating Die and Starret Calipers, so I doubt that my equipment is off.
As I mentioned earlier, I am seating my bullets to a COAL of 2.245 and set up my die accordingly, however, the loaded rounds often measure 2.245. It may be 2.243, 44, 46, 47. They are never below 2.243 or longer than 2.247. I triple checked my equipment and nothing is off, so the only thing I can think of is that the V-Max's plastic tip varies slightly from one to the next. My primers are seated properly so what else could it be?
I would love to hear your thoughts on this and what you would advise.
Thanks!!
Frank

You got it. The COAL typically varies from one round to the next, because of differences in the tips. The most critical is that the Ogive measurements are the same, which often vary slightly even.

Happy I'm not crazy then!

How do measure from the ogive instead of the tip with my calipers then?

Or do you even bother with such a slight discrepancy?

Thanks Graybird

You need a bullet comparator to measure the Ogive of a bullet. However, if you're getting the accuracy you described, who gives a flying flip about a few measurements! I say keep doing what you're doing and enjoy your success!!!

Agreed. I just spent a ton of money getting set-up

If I do go the comparator route, I guess that you would load a round, measure with the comp and then set up the die from that?

I use my comparators to get a certain distance from the rifle lands for my rifle. Once I settle on a particular powder charge. I use the comparators to adjust seating depth to fine tune the load to what the rifle desires for maximum accuracy.

quote:

Originally posted by Leopardtrack:
If I do go the comparator route, I guess that you would load a round, measure with the comp and then set up the die from that?

It is common to find the maximum possible length with the the bullet just touching the lands. That length becomes the reference. Then set the length of the loaded round will always be that value or less. The magazine length and seating depth to ensure a firm grip on the bullet often are major determinants of OAL rather than the distance to the lands.

Got it. So since I know the COAL I want (2.245)
do I just now determine my new (according to the different comparator COAL reading) COAL according to the comparator?

I now use a comparator. It gives consistant reading.

I just make up a dummy round with empty case & no primer & keep adjusting seating until the coparator gives me the desired length. I also check mag length & bullet lead - all hunting ammo is 30 thou off lands. 222 Rem is the only one that I seat close to the lands for 0.5" 5 shot groups at 100 meters.

I used the same method before I got the comparator & I always had variances in measurement due to tip deformation.

quote:

Originally posted by Leopardtrack:
Got it. So since I know the COAL I want (2.245)
do I just now determine my new (according to the different comparator COAL reading) COAL according to the comparator?

Yes. The comparator can read the dimension right off of the ogive of your reference round.
If your seater punch contacts the ogive reasonably close to the same location contacted by the comparator you will get uniform results.

But just for grins sit down with your comparator and measure 50 bullets (projectiles only not loaded rounds) from the base to the ogive. You will still find they vary.

If you get ate up with measureing and experiments take a group of bullets that have the same length from base to ogive and load and shoot. See if you can tell any difference.

COL can also vary if you're not putting consistent pressure on your seating stroke. I noticed with my 9mm, if I pushed just a little harder on some, the COL would be a little shorter. Also notices when Im nearing the last round, and there is no casing in the other stations (progressive), the shell plate flexes more which seats the bullet deeper.
Still though, I loaded some 9mm at .1145, 1.150, 1.155, 1.160, 1.165, and 1.167 and all of them cycled fine. Dont know about loading with that great a varying COL because the ammount of powder would need to be adjusted for the pressure differences.

Just a new guy observation. Not sure if this is even right, just what I noticed.